CARA'S TIPSReproduction, animal improvement, nutrition and ration formulation
JAMBWAECNECO
What the syllabus asks
JAMB: C4 reproduction, C5 animal nutrition, C10 animal improvement, A4 genetics in agriculture
WAEC: H Reproduction in farm animals (puberty, oestrous cycle, mating, artificial insemination, egg formation and incubation); animal improvement (selection, breeding systems, crossbreeding, upgrading, AI); animal nutrition (classes of nutrients, feeds and feedstuffs, rations, malnutrition and deficiency diseases); Practical D4 (feeds and feedstuffs)
NECO: H Reproduction in farm animals (puberty, oestrous cycle, mating, artificial insemination, egg formation and incubation); animal improvement (selection, breeding systems, crossbreeding, upgrading, AI); animal nutrition (classes of nutrients, feeds and feedstuffs, rations, malnutrition and deficiency diseases); Practical D4 (feeds and feedstuffs)
What you will learn
- Explain puberty, mating systems and the advantages of AI.
- Describe egg incubation, natural and artificial.
- Define selection and describe breeding systems with merits and demerits.
- Explain heterosis and the use of crossbreeding and upgrading in Nigeria.
- State the classes of nutrients, their sources and functions in farm animals.
- Classify feeds and describe roughages, concentrates and additives.
- Distinguish maintenance and production rations and formulate a simple ration by Pearson square.
- Describe common nutritional deficiency diseases and their prevention.
Key points
- Breed females at adequate body size, not at first puberty.
- Mating: flock, pen, hand, stud; flushing before mating, steaming up before birth.
- AI: collect, evaluate, extend, store at −196 °C, inseminate at the right time.
- AI spreads superior genes widely but needs skill, equipment and good heat detection.
- Chicken eggs hatch in 21 days; incubator about 37.5 °C, 55–60% RH, turning, ventilation; candle eggs.
- Selection methods: mass, pedigree, progeny testing, family; cull poor animals.
- Breeding systems: inbreeding, line breeding, outbreeding, outcrossing, crossbreeding, upgrading.
- Upgrading reaches ⅞ improved genes after three generations; heterosis = crossbred above mid-parent.
- Nutrients: carbohydrates, fats, proteins, vitamins, minerals, water.
- Deficiencies: rickets (D, Ca, P), milk fever (Ca), anaemia (Fe), goitre (I), curled-toe (B₂), perosis (Mn).
- Feeds: roughages, energy and protein concentrates, supplements, additives.
- Pearson square: subtract diagonally; parts → percentages; check CP.
- FCR = feed ÷ gain; CP = N × 6.25; digestibility = (eaten − faeces) ÷ eaten × 100.
- Dry-season feeding: hay, silage, residues, fodder banks, urea-molasses blocks.
Start here: Puberty, mating and reproductive management
Puberty and age at first service
Puberty is when an animal first produces viable gametes and shows heat (females) or can mate (males). It depends on species, breed, nutrition, health and season. Animals should not be bred immediately at puberty; they are bred when they have reached a suitable body size (often about two-thirds of adult weight; flag: rule of thumb).
| Animal | Approximate age at first breeding |
|---|---|
| Cattle (local zebu) | About 2–3 years (later under poor nutrition); exotics earlier (flag: approximate) |
| Sheep and goats | About 8–12 months |
| Pigs (gilts) | About 7–8 months |
| Rabbits | About 5–6 months |
| Chickens (layers) | Point of lay about 18–20 weeks |
Methods of natural mating
- Flock/herd mating: males run freely with females. Cheap, but parentage is unknown and records are poor.
- Pen mating: one selected male kept with a group of females in a pen. Parentage known.
- Hand mating: the female in heat is brought to the male (or the doe taken to the buck’s hutch in rabbits) and removed after service. Controls mating and allows records.
- Stud mating: a farmer pays to use a superior male.
Reproductive management
- Observe heat twice daily and keep breeding records.
- Flushing: increase the plane of nutrition of females two to three weeks before mating to raise ovulation rate and litter size.
- Steaming up: extra feed to females in late pregnancy for foetal growth and milk production.
- Separate males to control breeding; correct male-to-female ratios.
- Prepare clean maternity pens and assist at birth when necessary.
- Cull infertile animals.
Distinguish between flushing and steaming up.
Flushing is giving extra good feed to females shortly before and during the mating period to increase ovulation and conception rates (more twins or larger litters). Steaming up is extra feed in the last weeks of pregnancy to support rapid foetal growth, build body reserves and prepare for lactation.
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Practice questions
- flushing
- steaming up
- creep feeding
- culling
Show answer
A: flushing
Steaming up is feeding before giving birth.
- 28 days
- 14 days
- 35 days
- 21 days
Show answer
D: 21 days
Ducks and turkeys take about 28 days.
- grading
- turning
- candling
- brooding
Show answer
C: candling
Clear eggs are infertile.
- −80 °C
- −196 °C
- 0 °C
- −20 °C
Show answer
B: −196 °C
This is the boiling point of liquid nitrogen.
- one good male can serve many females
- it needs no skill
- it spreads diseases
- it is always cheaper than natural mating
Show answer
A: one good male can serve many females
It also avoids keeping many males.
Key words
- Puberty
- The age at which an animal first becomes capable of reproduction.
- Oestrus (heat)
- The period when a female is receptive to the male and ovulation occurs.
- Artificial insemination (AI)
- Collecting semen from a male and placing it in the female reproductive tract with instruments.
- Selection
- Choosing animals with desirable traits to be parents of the next generation.
- Inbreeding
- Mating of closely related animals, e.g. brother × sister.
- Line breeding
- A mild form of inbreeding to keep the genes of an outstanding ancestor.
- Outbreeding
- Mating of unrelated animals.
- Crossbreeding
- Mating animals of different breeds.
- Upgrading
- Repeated mating of local females and their offspring to pure-bred males of an improved breed.
- Heterosis (hybrid vigour)
- The superiority of crossbred offspring over the average of their parents.
- Heritability
- The proportion of variation in a trait that is due to genes and can be passed to offspring.
- Ration
- The total feed given to an animal in 24 hours.
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